DESCRIPTION:(Adapted from the Investigator's Abstract) Diisopropylphosphorofluoridate (DFP) and kainic acid (KA)-induced excessive stimulation of cholinergic and glutamatergic synapses, and increased production of radical oxygen species (ROS) are proposed to be implicated in the series of events linking status epilepticus with neuronal injury. One of the well-recognized targets of ROS-induced injury is peroxidation of lipids. Recently we found that F2-isoprostanes are produced in vivo by a non-cyclooxygenase mechanism involving ROS-catalyzed peroxidation of arachidonic acid. These compounds were increased in DFP-induced muscle injury. We can detect F2-isoprostanes by gas chromatography/negative-ion chemical ionization. Quantification of these compounds in piriform cortex, amygdala, and hippocampus provides a useful approach to determine whether ROS initiate the status epilepticus-induced neuronal injury by (1) establishing the temporal relationship between duration of status epilepticus, F2-isoprostanes production and injury using histochemistry and biochemical techniques, (2) assessing the metabolic conditions conducive to the production of ROS such as changes in the activities of cytochrome c oxidase and xanthine oxidase, (3) determining whether antioxidants and free radical scavengers prevent increases in F2-isoprostanes and injury such as the endogenous vitamin E and glutathione, inhibitors of xanthine oxidase such as allopurinol, N-Methyl-D-Aspartate (NMDA) receptor antagonists, and inhibitors of lipid peoxidation such as lazaroids, and (4) establishing whether F2-isoprostanes participate as pathophysiological mediators of oxidant injury by testing F2-isoprostanes as cause of injury. The previous data support the hypothesis that ROS play a causative role in DFP-induced neuronal necrosis, and the proposed studies should determine whether agents such as DFP and KA produce seizure-induce neuronal necrosis via ROS-induced lipid peroxidation and generation of F2 isoprostanes. As such, these studies will provide fundamental new insights into the molecular events underlying oxidant-induced injury as well as offer a therapeutic strategy for protection, namely treatment with antioxidants, and a new diagnostic approach since F2-isoprostanes can be detected in blood.